Reconstruction of the 3D Orientation of a Spinning Sounding Rocket by Detecting the Earth’s Horizon and Sun on Onboard Camera Images

Abstract

The paper describes the reconstruction of the 3D orientation of the spinning PMWE2F sounding rocket solely from the images of a side-looking camera. The Earth nadir vector, pointing to the centre of the Earth, is derived from the detected Earth’s horizon hyperbolae, and the Sun direction vector, pointing to the Sun, is derived from the detected Sun ellipses. The orientation is estimated using the TRIAD method when the Earth’s horizon and Sun are simultaneously visible, and by determining only two rotational degrees of freedom (DoF) and time interpolation of the third DoF in the meantime when only the Earth’s horizon is visible.